/* LzmaDec.c -- LZMA Decoder 2021-04-01 : Igor Pavlov : Public domain */ #include "Precomp.h" #include /* #include "CpuArch.h" */ #include "LzmaDec.h" #define kNumTopBits 24 #define kTopValue ((UInt32)1 << kNumTopBits) #define kNumBitModelTotalBits 11 #define kBitModelTotal (1 << kNumBitModelTotalBits) #define RC_INIT_SIZE 5 #ifndef _LZMA_DEC_OPT #define kNumMoveBits 5 #define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); } #define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound) #define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits)); #define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits)); #define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \ { UPDATE_0(p); i = (i + i); A0; } else \ { UPDATE_1(p); i = (i + i) + 1; A1; } #define TREE_GET_BIT(probs, i) { GET_BIT2(probs + i, i, ;, ;); } #define REV_BIT(p, i, A0, A1) IF_BIT_0(p + i) \ { UPDATE_0(p + i); A0; } else \ { UPDATE_1(p + i); A1; } #define REV_BIT_VAR( p, i, m) REV_BIT(p, i, i += m; m += m, m += m; i += m; ) #define REV_BIT_CONST(p, i, m) REV_BIT(p, i, i += m; , i += m * 2; ) #define REV_BIT_LAST( p, i, m) REV_BIT(p, i, i -= m , ; ) #define TREE_DECODE(probs, limit, i) \ { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; } /* #define _LZMA_SIZE_OPT */ #ifdef _LZMA_SIZE_OPT #define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i) #else #define TREE_6_DECODE(probs, i) \ { i = 1; \ TREE_GET_BIT(probs, i); \ TREE_GET_BIT(probs, i); \ TREE_GET_BIT(probs, i); \ TREE_GET_BIT(probs, i); \ TREE_GET_BIT(probs, i); \ TREE_GET_BIT(probs, i); \ i -= 0x40; } #endif #define NORMAL_LITER_DEC TREE_GET_BIT(prob, symbol) #define MATCHED_LITER_DEC \ matchByte += matchByte; \ bit = offs; \ offs &= matchByte; \ probLit = prob + (offs + bit + symbol); \ GET_BIT2(probLit, symbol, offs ^= bit; , ;) #endif // _LZMA_DEC_OPT #define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_INPUT_EOF; range <<= 8; code = (code << 8) | (*buf++); } #define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound) #define UPDATE_0_CHECK range = bound; #define UPDATE_1_CHECK range -= bound; code -= bound; #define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \ { UPDATE_0_CHECK; i = (i + i); A0; } else \ { UPDATE_1_CHECK; i = (i + i) + 1; A1; } #define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;) #define TREE_DECODE_CHECK(probs, limit, i) \ { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; } #define REV_BIT_CHECK(p, i, m) IF_BIT_0_CHECK(p + i) \ { UPDATE_0_CHECK; i += m; m += m; } else \ { UPDATE_1_CHECK; m += m; i += m; } #define kNumPosBitsMax 4 #define kNumPosStatesMax (1 << kNumPosBitsMax) #define kLenNumLowBits 3 #define kLenNumLowSymbols (1 << kLenNumLowBits) #define kLenNumHighBits 8 #define kLenNumHighSymbols (1 << kLenNumHighBits) #define LenLow 0 #define LenHigh (LenLow + 2 * (kNumPosStatesMax << kLenNumLowBits)) #define kNumLenProbs (LenHigh + kLenNumHighSymbols) #define LenChoice LenLow #define LenChoice2 (LenLow + (1 << kLenNumLowBits)) #define kNumStates 12 #define kNumStates2 16 #define kNumLitStates 7 #define kStartPosModelIndex 4 #define kEndPosModelIndex 14 #define kNumFullDistances (1 << (kEndPosModelIndex >> 1)) #define kNumPosSlotBits 6 #define kNumLenToPosStates 4 #define kNumAlignBits 4 #define kAlignTableSize (1 << kNumAlignBits) #define kMatchMinLen 2 #define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols * 2 + kLenNumHighSymbols) #define kMatchSpecLen_Error_Data (1 << 9) #define kMatchSpecLen_Error_Fail (kMatchSpecLen_Error_Data - 1) /* External ASM code needs same CLzmaProb array layout. So don't change it. */ /* (probs_1664) is faster and better for code size at some platforms */ /* #ifdef MY_CPU_X86_OR_AMD64 */ #define kStartOffset 1664 #define GET_PROBS p->probs_1664 /* #define GET_PROBS p->probs + kStartOffset #else #define kStartOffset 0 #define GET_PROBS p->probs #endif */ #define SpecPos (-kStartOffset) #define IsRep0Long (SpecPos + kNumFullDistances) #define RepLenCoder (IsRep0Long + (kNumStates2 << kNumPosBitsMax)) #define LenCoder (RepLenCoder + kNumLenProbs) #define IsMatch (LenCoder + kNumLenProbs) #define Align (IsMatch + (kNumStates2 << kNumPosBitsMax)) #define IsRep (Align + kAlignTableSize) #define IsRepG0 (IsRep + kNumStates) #define IsRepG1 (IsRepG0 + kNumStates) #define IsRepG2 (IsRepG1 + kNumStates) #define PosSlot (IsRepG2 + kNumStates) #define Literal (PosSlot + (kNumLenToPosStates << kNumPosSlotBits)) #define NUM_BASE_PROBS (Literal + kStartOffset) #if Align != 0 && kStartOffset != 0 #error Stop_Compiling_Bad_LZMA_kAlign #endif #if NUM_BASE_PROBS != 1984 #error Stop_Compiling_Bad_LZMA_PROBS #endif #define LZMA_LIT_SIZE 0x300 #define LzmaProps_GetNumProbs(p) (NUM_BASE_PROBS + ((UInt32)LZMA_LIT_SIZE << ((p)->lc + (p)->lp))) #define CALC_POS_STATE(processedPos, pbMask) (((processedPos) & (pbMask)) << 4) #define COMBINED_PS_STATE (posState + state) #define GET_LEN_STATE (posState) #define LZMA_DIC_MIN (1 << 12) /* p->remainLen : shows status of LZMA decoder: < kMatchSpecLenStart : the number of bytes to be copied with (p->rep0) offset = kMatchSpecLenStart : the LZMA stream was finished with end mark = kMatchSpecLenStart + 1 : need init range coder = kMatchSpecLenStart + 2 : need init range coder and state = kMatchSpecLen_Error_Fail : Internal Code Failure = kMatchSpecLen_Error_Data + [0 ... 273] : LZMA Data Error */ /* ---------- LZMA_DECODE_REAL ---------- */ /* LzmaDec_DecodeReal_3() can be implemented in external ASM file. 3 - is the code compatibility version of that function for check at link time. */ #define LZMA_DECODE_REAL LzmaDec_DecodeReal_3 /* LZMA_DECODE_REAL() In: RangeCoder is normalized if (p->dicPos == limit) { LzmaDec_TryDummy() was called before to exclude LITERAL and MATCH-REP cases. So first symbol can be only MATCH-NON-REP. And if that MATCH-NON-REP symbol is not END_OF_PAYALOAD_MARKER, then the function doesn't write any byte to dictionary, the function returns SZ_OK, and the caller can use (p->remainLen) and (p->reps[0]) later. } Processing: The first LZMA symbol will be decoded in any case. All main checks for limits are at the end of main loop, It decodes additional LZMA-symbols while (p->buf < bufLimit && dicPos < limit), RangeCoder is still without last normalization when (p->buf < bufLimit) is being checked. But if (p->buf < bufLimit), the caller provided at least (LZMA_REQUIRED_INPUT_MAX + 1) bytes for next iteration before limit (bufLimit + LZMA_REQUIRED_INPUT_MAX), that is enough for worst case LZMA symbol with one additional RangeCoder normalization for one bit. So that function never reads bufLimit [LZMA_REQUIRED_INPUT_MAX] byte. Out: RangeCoder is normalized Result: SZ_OK - OK p->remainLen: < kMatchSpecLenStart : the number of bytes to be copied with (p->reps[0]) offset = kMatchSpecLenStart : the LZMA stream was finished with end mark SZ_ERROR_DATA - error, when the MATCH-Symbol refers out of dictionary p->remainLen : undefined p->reps[*] : undefined */ #ifdef _LZMA_DEC_OPT int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit); #else static int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit) { CLzmaProb *probs = GET_PROBS; unsigned state = (unsigned)p->state; UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3]; unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1; unsigned lc = p->prop.lc; unsigned lpMask = ((unsigned)0x100 << p->prop.lp) - ((unsigned)0x100 >> lc); Byte *dic = p->dic; SizeT dicBufSize = p->dicBufSize; SizeT dicPos = p->dicPos; UInt32 processedPos = p->processedPos; UInt32 checkDicSize = p->checkDicSize; unsigned len = 0; const Byte *buf = p->buf; UInt32 range = p->range; UInt32 code = p->code; do { CLzmaProb *prob; UInt32 bound; unsigned ttt; unsigned posState = CALC_POS_STATE(processedPos, pbMask); prob = probs + IsMatch + COMBINED_PS_STATE; IF_BIT_0(prob) { unsigned symbol; UPDATE_0(prob); prob = probs + Literal; if (processedPos != 0 || checkDicSize != 0) prob += (UInt32)3 * ((((processedPos << 8) + dic[(dicPos == 0 ? dicBufSize : dicPos) - 1]) & lpMask) << lc); processedPos++; if (state < kNumLitStates) { state -= (state < 4) ? state : 3; symbol = 1; #ifdef _LZMA_SIZE_OPT do { NORMAL_LITER_DEC } while (symbol < 0x100); #else NORMAL_LITER_DEC NORMAL_LITER_DEC NORMAL_LITER_DEC NORMAL_LITER_DEC NORMAL_LITER_DEC NORMAL_LITER_DEC NORMAL_LITER_DEC NORMAL_LITER_DEC #endif } else { unsigned matchByte = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)]; unsigned offs = 0x100; state -= (state < 10) ? 3 : 6; symbol = 1; #ifdef _LZMA_SIZE_OPT do { unsigned bit; CLzmaProb *probLit; MATCHED_LITER_DEC } while (symbol < 0x100); #else { unsigned bit; CLzmaProb *probLit; MATCHED_LITER_DEC MATCHED_LITER_DEC MATCHED_LITER_DEC MATCHED_LITER_DEC MATCHED_LITER_DEC MATCHED_LITER_DEC MATCHED_LITER_DEC MATCHED_LITER_DEC } #endif } dic[dicPos++] = (Byte)symbol; continue; } { UPDATE_1(prob); prob = probs + IsRep + state; IF_BIT_0(prob) { UPDATE_0(prob); state += kNumStates; prob = probs + LenCoder; } else { UPDATE_1(prob); prob = probs + IsRepG0 + state; IF_BIT_0(prob) { UPDATE_0(prob); prob = probs + IsRep0Long + COMBINED_PS_STATE; IF_BIT_0(prob) { UPDATE_0(prob); // that case was checked before with kBadRepCode // if (checkDicSize == 0 && processedPos == 0) { len = kMatchSpecLen_Error_Data + 1; break; } // The caller doesn't allow (dicPos == limit) case here // so we don't need the following check: // if (dicPos == limit) { state = state < kNumLitStates ? 9 : 11; len = 1; break; } dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)]; dicPos++; processedPos++; state = state < kNumLitStates ? 9 : 11; continue; } UPDATE_1(prob); } else { UInt32 distance; UPDATE_1(prob); prob = probs + IsRepG1 + state; IF_BIT_0(prob) { UPDATE_0(prob); distance = rep1; } else { UPDATE_1(prob); prob = probs + IsRepG2 + state; IF_BIT_0(prob) { UPDATE_0(prob); distance = rep2; } else { UPDATE_1(prob); distance = rep3; rep3 = rep2; } rep2 = rep1; } rep1 = rep0; rep0 = distance; } state = state < kNumLitStates ? 8 : 11; prob = probs + RepLenCoder; } #ifdef _LZMA_SIZE_OPT { unsigned lim, offset; CLzmaProb *probLen = prob + LenChoice; IF_BIT_0(probLen) { UPDATE_0(probLen); probLen = prob + LenLow + GET_LEN_STATE; offset = 0; lim = (1 << kLenNumLowBits); } else { UPDATE_1(probLen); probLen = prob + LenChoice2; IF_BIT_0(probLen) { UPDATE_0(probLen); probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits); offset = kLenNumLowSymbols; lim = (1 << kLenNumLowBits); } else { UPDATE_1(probLen); probLen = prob + LenHigh; offset = kLenNumLowSymbols * 2; lim = (1 << kLenNumHighBits); } } TREE_DECODE(probLen, lim, len); len += offset; } #else { CLzmaProb *probLen = prob + LenChoice; IF_BIT_0(probLen) { UPDATE_0(probLen); probLen = prob + LenLow + GET_LEN_STATE; len = 1; TREE_GET_BIT(probLen, len); TREE_GET_BIT(probLen, len); TREE_GET_BIT(probLen, len); len -= 8; } else { UPDATE_1(probLen); probLen = prob + LenChoice2; IF_BIT_0(probLen) { UPDATE_0(probLen); probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits); len = 1; TREE_GET_BIT(probLen, len); TREE_GET_BIT(probLen, len); TREE_GET_BIT(probLen, len); } else { UPDATE_1(probLen); probLen = prob + LenHigh; TREE_DECODE(probLen, (1 << kLenNumHighBits), len); len += kLenNumLowSymbols * 2; } } } #endif if (state >= kNumStates) { UInt32 distance; prob = probs + PosSlot + ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits); TREE_6_DECODE(prob, distance); if (distance >= kStartPosModelIndex) { unsigned posSlot = (unsigned)distance; unsigned numDirectBits = (unsigned)(((distance >> 1) - 1)); distance = (2 | (distance & 1)); if (posSlot < kEndPosModelIndex) { distance <<= numDirectBits; prob = probs + SpecPos; { UInt32 m = 1; distance++; do { REV_BIT_VAR(prob, distance, m); } while (--numDirectBits); distance -= m; } } else { numDirectBits -= kNumAlignBits; do { NORMALIZE range >>= 1; { UInt32 t; code -= range; t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */ distance = (distance << 1) + (t + 1); code += range & t; } /* distance <<= 1; if (code >= range) { code -= range; distance |= 1; } */ } while (--numDirectBits); prob = probs + Align; distance <<= kNumAlignBits; { unsigned i = 1; REV_BIT_CONST(prob, i, 1); REV_BIT_CONST(prob, i, 2); REV_BIT_CONST(prob, i, 4); REV_BIT_LAST (prob, i, 8); distance |= i; } if (distance == (UInt32)0xFFFFFFFF) { len = kMatchSpecLenStart; state -= kNumStates; break; } } } rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance + 1; state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3; if (distance >= (checkDicSize == 0 ? processedPos: checkDicSize)) { len += kMatchSpecLen_Error_Data + kMatchMinLen; // len = kMatchSpecLen_Error_Data; // len += kMatchMinLen; break; } } len += kMatchMinLen; { SizeT rem; unsigned curLen; SizeT pos; if ((rem = limit - dicPos) == 0) { /* We stop decoding and return SZ_OK, and we can resume decoding later. Any error conditions can be tested later in caller code. For more strict mode we can stop decoding with error // len += kMatchSpecLen_Error_Data; */ break; } curLen = ((rem < len) ? (unsigned)rem : len); pos = dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0); processedPos += (UInt32)curLen; len -= curLen; if (curLen <= dicBufSize - pos) { Byte *dest = dic + dicPos; ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos; const Byte *lim = dest + curLen; dicPos += (SizeT)curLen; do *(dest) = (Byte)*(dest + src); while (++dest != lim); } else { do { dic[dicPos++] = dic[pos]; if (++pos == dicBufSize) pos = 0; } while (--curLen != 0); } } } } while (dicPos < limit && buf < bufLimit); NORMALIZE; p->buf = buf; p->range = range; p->code = code; p->remainLen = (UInt32)len; // & (kMatchSpecLen_Error_Data - 1); // we can write real length for error matches too. p->dicPos = dicPos; p->processedPos = processedPos; p->reps[0] = rep0; p->reps[1] = rep1; p->reps[2] = rep2; p->reps[3] = rep3; p->state = (UInt32)state; if (len >= kMatchSpecLen_Error_Data) return SZ_ERROR_DATA; return SZ_OK; } #endif static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit) { unsigned len = (unsigned)p->remainLen; if (len == 0 /* || len >= kMatchSpecLenStart */) return; { SizeT dicPos = p->dicPos; Byte *dic; SizeT dicBufSize; SizeT rep0; /* we use SizeT to avoid the BUG of VC14 for AMD64 */ { SizeT rem = limit - dicPos; if (rem < len) { len = (unsigned)(rem); if (len == 0) return; } } if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len) p->checkDicSize = p->prop.dicSize; p->processedPos += (UInt32)len; p->remainLen -= (UInt32)len; dic = p->dic; rep0 = p->reps[0]; dicBufSize = p->dicBufSize; do { dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)]; dicPos++; } while (--len); p->dicPos = dicPos; } } /* At staring of new stream we have one of the following symbols: - Literal - is allowed - Non-Rep-Match - is allowed only if it's end marker symbol - Rep-Match - is not allowed We use early check of (RangeCoder:Code) over kBadRepCode to simplify main decoding code */ #define kRange0 0xFFFFFFFF #define kBound0 ((kRange0 >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1)) #define kBadRepCode (kBound0 + (((kRange0 - kBound0) >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1))) #if kBadRepCode != (0xC0000000 - 0x400) #error Stop_Compiling_Bad_LZMA_Check #endif /* LzmaDec_DecodeReal2(): It calls LZMA_DECODE_REAL() and it adjusts limit according (p->checkDicSize). We correct (p->checkDicSize) after LZMA_DECODE_REAL() and in LzmaDec_WriteRem(), and we support the following state of (p->checkDicSize): if (total_processed < p->prop.dicSize) then { (total_processed == p->processedPos) (p->checkDicSize == 0) } else (p->checkDicSize == p->prop.dicSize) */ static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit) { if (p->checkDicSize == 0) { UInt32 rem = p->prop.dicSize - p->processedPos; if (limit - p->dicPos > rem) limit = p->dicPos + rem; } { int res = LZMA_DECODE_REAL(p, limit, bufLimit); if (p->checkDicSize == 0 && p->processedPos >= p->prop.dicSize) p->checkDicSize = p->prop.dicSize; return res; } } typedef enum { DUMMY_INPUT_EOF, /* need more input data */ DUMMY_LIT, DUMMY_MATCH, DUMMY_REP } ELzmaDummy; #define IS_DUMMY_END_MARKER_POSSIBLE(dummyRes) ((dummyRes) == DUMMY_MATCH) static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, const Byte **bufOut) { UInt32 range = p->range; UInt32 code = p->code; const Byte *bufLimit = *bufOut; const CLzmaProb *probs = GET_PROBS; unsigned state = (unsigned)p->state; ELzmaDummy res; for (;;) { const CLzmaProb *prob; UInt32 bound; unsigned ttt; unsigned posState = CALC_POS_STATE(p->processedPos, ((unsigned)1 << p->prop.pb) - 1); prob = probs + IsMatch + COMBINED_PS_STATE; IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK prob = probs + Literal; if (p->checkDicSize != 0 || p->processedPos != 0) prob += ((UInt32)LZMA_LIT_SIZE * ((((p->processedPos) & (((unsigned)1 << (p->prop.lp)) - 1)) << p->prop.lc) + ((unsigned)p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc)))); if (state < kNumLitStates) { unsigned symbol = 1; do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100); } else { unsigned matchByte = p->dic[p->dicPos - p->reps[0] + (p->dicPos < p->reps[0] ? p->dicBufSize : 0)]; unsigned offs = 0x100; unsigned symbol = 1; do { unsigned bit; const CLzmaProb *probLit; matchByte += matchByte; bit = offs; offs &= matchByte; probLit = prob + (offs + bit + symbol); GET_BIT2_CHECK(probLit, symbol, offs ^= bit; , ; ) } while (symbol < 0x100); } res = DUMMY_LIT; } else { unsigned len; UPDATE_1_CHECK; prob = probs + IsRep + state; IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; state = 0; prob = probs + LenCoder; res = DUMMY_MATCH; } else { UPDATE_1_CHECK; res = DUMMY_REP; prob = probs + IsRepG0 + state; IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; prob = probs + IsRep0Long + COMBINED_PS_STATE; IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; break; } else { UPDATE_1_CHECK; } } else { UPDATE_1_CHECK; prob = probs + IsRepG1 + state; IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; } else { UPDATE_1_CHECK; prob = probs + IsRepG2 + state; IF_BIT_0_CHECK(prob) { UPDATE_0_CHECK; } else { UPDATE_1_CHECK; } } } state = kNumStates; prob = probs + RepLenCoder; } { unsigned limit, offset; const CLzmaProb *probLen = prob + LenChoice; IF_BIT_0_CHECK(probLen) { UPDATE_0_CHECK; probLen = prob + LenLow + GET_LEN_STATE; offset = 0; limit = 1 << kLenNumLowBits; } else { UPDATE_1_CHECK; probLen = prob + LenChoice2; IF_BIT_0_CHECK(probLen) { UPDATE_0_CHECK; probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits); offset = kLenNumLowSymbols; limit = 1 << kLenNumLowBits; } else { UPDATE_1_CHECK; probLen = prob + LenHigh; offset = kLenNumLowSymbols * 2; limit = 1 << kLenNumHighBits; } } TREE_DECODE_CHECK(probLen, limit, len); len += offset; } if (state < 4) { unsigned posSlot; prob = probs + PosSlot + ((len < kNumLenToPosStates - 1 ? len : kNumLenToPosStates - 1) << kNumPosSlotBits); TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot); if (posSlot >= kStartPosModelIndex) { unsigned numDirectBits = ((posSlot >> 1) - 1); if (posSlot < kEndPosModelIndex) { prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits); } else { numDirectBits -= kNumAlignBits; do { NORMALIZE_CHECK range >>= 1; code -= range & (((code - range) >> 31) - 1); /* if (code >= range) code -= range; */ } while (--numDirectBits); prob = probs + Align; numDirectBits = kNumAlignBits; } { unsigned i = 1; unsigned m = 1; do { REV_BIT_CHECK(prob, i, m); } while (--numDirectBits); } } } } break; } NORMALIZE_CHECK; *bufOut = buf; return res; } void LzmaDec_InitDicAndState(CLzmaDec *p, BoolInt initDic, BoolInt initState); void LzmaDec_InitDicAndState(CLzmaDec *p, BoolInt initDic, BoolInt initState) { p->remainLen = kMatchSpecLenStart + 1; p->tempBufSize = 0; if (initDic) { p->processedPos = 0; p->checkDicSize = 0; p->remainLen = kMatchSpecLenStart + 2; } if (initState) p->remainLen = kMatchSpecLenStart + 2; } void LzmaDec_Init(CLzmaDec *p) { p->dicPos = 0; LzmaDec_InitDicAndState(p, True, True); } /* LZMA supports optional end_marker. So the decoder can lookahead for one additional LZMA-Symbol to check end_marker. That additional LZMA-Symbol can require up to LZMA_REQUIRED_INPUT_MAX bytes in input stream. When the decoder reaches dicLimit, it looks (finishMode) parameter: if (finishMode == LZMA_FINISH_ANY), the decoder doesn't lookahead if (finishMode != LZMA_FINISH_ANY), the decoder lookahead, if end_marker is possible for current position When the decoder lookahead, and the lookahead symbol is not end_marker, we have two ways: 1) Strict mode (default) : the decoder returns SZ_ERROR_DATA. 2) The relaxed mode (alternative mode) : we could return SZ_OK, and the caller must check (status) value. The caller can show the error, if the end of stream is expected, and the (status) is noit LZMA_STATUS_FINISHED_WITH_MARK or LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK. */ #define RETURN__NOT_FINISHED__FOR_FINISH \ *status = LZMA_STATUS_NOT_FINISHED; \ return SZ_ERROR_DATA; // for strict mode // return SZ_OK; // for relaxed mode SRes LzmaDec_DecodeToDic(CLzmaDec *p, SizeT dicLimit, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status) { SizeT inSize = *srcLen; (*srcLen) = 0; *status = LZMA_STATUS_NOT_SPECIFIED; if (p->remainLen > kMatchSpecLenStart) { if (p->remainLen > kMatchSpecLenStart + 2) return p->remainLen == kMatchSpecLen_Error_Fail ? SZ_ERROR_FAIL : SZ_ERROR_DATA; for (; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--) p->tempBuf[p->tempBufSize++] = *src++; if (p->tempBufSize != 0 && p->tempBuf[0] != 0) return SZ_ERROR_DATA; if (p->tempBufSize < RC_INIT_SIZE) { *status = LZMA_STATUS_NEEDS_MORE_INPUT; return SZ_OK; } p->code = ((UInt32)p->tempBuf[1] << 24) | ((UInt32)p->tempBuf[2] << 16) | ((UInt32)p->tempBuf[3] << 8) | ((UInt32)p->tempBuf[4]); if (p->checkDicSize == 0 && p->processedPos == 0 && p->code >= kBadRepCode) return SZ_ERROR_DATA; p->range = 0xFFFFFFFF; p->tempBufSize = 0; if (p->remainLen > kMatchSpecLenStart + 1) { SizeT numProbs = LzmaProps_GetNumProbs(&p->prop); SizeT i; CLzmaProb *probs = p->probs; for (i = 0; i < numProbs; i++) probs[i] = kBitModelTotal >> 1; p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1; p->state = 0; } p->remainLen = 0; } for (;;) { if (p->remainLen == kMatchSpecLenStart) { if (p->code != 0) return SZ_ERROR_DATA; *status = LZMA_STATUS_FINISHED_WITH_MARK; return SZ_OK; } LzmaDec_WriteRem(p, dicLimit); { // (p->remainLen == 0 || p->dicPos == dicLimit) int checkEndMarkNow = 0; if (p->dicPos >= dicLimit) { if (p->remainLen == 0 && p->code == 0) { *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK; return SZ_OK; } if (finishMode == LZMA_FINISH_ANY) { *status = LZMA_STATUS_NOT_FINISHED; return SZ_OK; } if (p->remainLen != 0) { RETURN__NOT_FINISHED__FOR_FINISH; } checkEndMarkNow = 1; } // (p->remainLen == 0) if (p->tempBufSize == 0) { const Byte *bufLimit; int dummyProcessed = -1; if (inSize < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow) { const Byte *bufOut = src + inSize; ELzmaDummy dummyRes = LzmaDec_TryDummy(p, src, &bufOut); if (dummyRes == DUMMY_INPUT_EOF) { size_t i; if (inSize >= LZMA_REQUIRED_INPUT_MAX) break; (*srcLen) += inSize; p->tempBufSize = (unsigned)inSize; for (i = 0; i < inSize; i++) p->tempBuf[i] = src[i]; *status = LZMA_STATUS_NEEDS_MORE_INPUT; return SZ_OK; } dummyProcessed = (int)(bufOut - src); if ((unsigned)dummyProcessed > LZMA_REQUIRED_INPUT_MAX) break; if (checkEndMarkNow && !IS_DUMMY_END_MARKER_POSSIBLE(dummyRes)) { unsigned i; (*srcLen) += (unsigned)dummyProcessed; p->tempBufSize = (unsigned)dummyProcessed; for (i = 0; i < (unsigned)dummyProcessed; i++) p->tempBuf[i] = src[i]; // p->remainLen = kMatchSpecLen_Error_Data; RETURN__NOT_FINISHED__FOR_FINISH; } bufLimit = src; // we will decode only one iteration } else bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX; p->buf = src; { int res = LzmaDec_DecodeReal2(p, dicLimit, bufLimit); SizeT processed = (SizeT)(p->buf - src); if (dummyProcessed < 0) { if (processed > inSize) break; } else if ((unsigned)dummyProcessed != processed) break; src += processed; inSize -= processed; (*srcLen) += processed; if (res != SZ_OK) { p->remainLen = kMatchSpecLen_Error_Data; return SZ_ERROR_DATA; } } continue; } { // we have some data in (p->tempBuf) // in strict mode: tempBufSize is not enough for one Symbol decoding. // in relaxed mode: tempBufSize not larger than required for one Symbol decoding. unsigned rem = p->tempBufSize; unsigned ahead = 0; int dummyProcessed = -1; while (rem < LZMA_REQUIRED_INPUT_MAX && ahead < inSize) p->tempBuf[rem++] = src[ahead++]; // ahead - the size of new data copied from (src) to (p->tempBuf) // rem - the size of temp buffer including new data from (src) if (rem < LZMA_REQUIRED_INPUT_MAX || checkEndMarkNow) { const Byte *bufOut = p->tempBuf + rem; ELzmaDummy dummyRes = LzmaDec_TryDummy(p, p->tempBuf, &bufOut); if (dummyRes == DUMMY_INPUT_EOF) { if (rem >= LZMA_REQUIRED_INPUT_MAX) break; p->tempBufSize = rem; (*srcLen) += (SizeT)ahead; *status = LZMA_STATUS_NEEDS_MORE_INPUT; return SZ_OK; } dummyProcessed = (int)(bufOut - p->tempBuf); if ((unsigned)dummyProcessed < p->tempBufSize) break; if (checkEndMarkNow && !IS_DUMMY_END_MARKER_POSSIBLE(dummyRes)) { (*srcLen) += (unsigned)dummyProcessed - p->tempBufSize; p->tempBufSize = (unsigned)dummyProcessed; // p->remainLen = kMatchSpecLen_Error_Data; RETURN__NOT_FINISHED__FOR_FINISH; } } p->buf = p->tempBuf; { // we decode one symbol from (p->tempBuf) here, so the (bufLimit) is equal to (p->buf) int res = LzmaDec_DecodeReal2(p, dicLimit, p->buf); SizeT processed = (SizeT)(p->buf - p->tempBuf); rem = p->tempBufSize; if (dummyProcessed < 0) { if (processed > LZMA_REQUIRED_INPUT_MAX) break; if (processed < rem) break; } else if ((unsigned)dummyProcessed != processed) break; processed -= rem; src += processed; inSize -= processed; (*srcLen) += processed; p->tempBufSize = 0; if (res != SZ_OK) { p->remainLen = kMatchSpecLen_Error_Data; return SZ_ERROR_DATA; } } } } } /* Some unexpected error: internal error of code, memory corruption or hardware failure */ p->remainLen = kMatchSpecLen_Error_Fail; return SZ_ERROR_FAIL; } SRes LzmaDec_DecodeToBuf(CLzmaDec *p, Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, ELzmaFinishMode finishMode, ELzmaStatus *status) { SizeT outSize = *destLen; SizeT inSize = *srcLen; *srcLen = *destLen = 0; for (;;) { SizeT inSizeCur = inSize, outSizeCur, dicPos; ELzmaFinishMode curFinishMode; SRes res; if (p->dicPos == p->dicBufSize) p->dicPos = 0; dicPos = p->dicPos; if (outSize > p->dicBufSize - dicPos) { outSizeCur = p->dicBufSize; curFinishMode = LZMA_FINISH_ANY; } else { outSizeCur = dicPos + outSize; curFinishMode = finishMode; } res = LzmaDec_DecodeToDic(p, outSizeCur, src, &inSizeCur, curFinishMode, status); src += inSizeCur; inSize -= inSizeCur; *srcLen += inSizeCur; outSizeCur = p->dicPos - dicPos; memcpy(dest, p->dic + dicPos, outSizeCur); dest += outSizeCur; outSize -= outSizeCur; *destLen += outSizeCur; if (res != 0) return res; if (outSizeCur == 0 || outSize == 0) return SZ_OK; } } void LzmaDec_FreeProbs(CLzmaDec *p, ISzAllocPtr alloc) { ISzAlloc_Free(alloc, p->probs); p->probs = NULL; } static void LzmaDec_FreeDict(CLzmaDec *p, ISzAllocPtr alloc) { ISzAlloc_Free(alloc, p->dic); p->dic = NULL; } void LzmaDec_Free(CLzmaDec *p, ISzAllocPtr alloc) { LzmaDec_FreeProbs(p, alloc); LzmaDec_FreeDict(p, alloc); } SRes LzmaProps_Decode(CLzmaProps *p, const Byte *data, unsigned size) { UInt32 dicSize; Byte d; if (size < LZMA_PROPS_SIZE) return SZ_ERROR_UNSUPPORTED; else dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24); if (dicSize < LZMA_DIC_MIN) dicSize = LZMA_DIC_MIN; p->dicSize = dicSize; d = data[0]; if (d >= (9 * 5 * 5)) return SZ_ERROR_UNSUPPORTED; p->lc = (Byte)(d % 9); d /= 9; p->pb = (Byte)(d / 5); p->lp = (Byte)(d % 5); return SZ_OK; } static SRes LzmaDec_AllocateProbs2(CLzmaDec *p, const CLzmaProps *propNew, ISzAllocPtr alloc) { UInt32 numProbs = LzmaProps_GetNumProbs(propNew); if (!p->probs || numProbs != p->numProbs) { LzmaDec_FreeProbs(p, alloc); p->probs = (CLzmaProb *)ISzAlloc_Alloc(alloc, numProbs * sizeof(CLzmaProb)); if (!p->probs) return SZ_ERROR_MEM; p->probs_1664 = p->probs + 1664; p->numProbs = numProbs; } return SZ_OK; } SRes LzmaDec_AllocateProbs(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc) { CLzmaProps propNew; RINOK(LzmaProps_Decode(&propNew, props, propsSize)); RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc)); p->prop = propNew; return SZ_OK; } SRes LzmaDec_Allocate(CLzmaDec *p, const Byte *props, unsigned propsSize, ISzAllocPtr alloc) { CLzmaProps propNew; SizeT dicBufSize; RINOK(LzmaProps_Decode(&propNew, props, propsSize)); RINOK(LzmaDec_AllocateProbs2(p, &propNew, alloc)); { UInt32 dictSize = propNew.dicSize; SizeT mask = ((UInt32)1 << 12) - 1; if (dictSize >= ((UInt32)1 << 30)) mask = ((UInt32)1 << 22) - 1; else if (dictSize >= ((UInt32)1 << 22)) mask = ((UInt32)1 << 20) - 1;; dicBufSize = ((SizeT)dictSize + mask) & ~mask; if (dicBufSize < dictSize) dicBufSize = dictSize; } if (!p->dic || dicBufSize != p->dicBufSize) { LzmaDec_FreeDict(p, alloc); p->dic = (Byte *)ISzAlloc_Alloc(alloc, dicBufSize); if (!p->dic) { LzmaDec_FreeProbs(p, alloc); return SZ_ERROR_MEM; } } p->dicBufSize = dicBufSize; p->prop = propNew; return SZ_OK; } SRes LzmaDecode(Byte *dest, SizeT *destLen, const Byte *src, SizeT *srcLen, const Byte *propData, unsigned propSize, ELzmaFinishMode finishMode, ELzmaStatus *status, ISzAllocPtr alloc) { CLzmaDec p; SRes res; SizeT outSize = *destLen, inSize = *srcLen; *destLen = *srcLen = 0; *status = LZMA_STATUS_NOT_SPECIFIED; if (inSize < RC_INIT_SIZE) return SZ_ERROR_INPUT_EOF; LzmaDec_Construct(&p); RINOK(LzmaDec_AllocateProbs(&p, propData, propSize, alloc)); p.dic = dest; p.dicBufSize = outSize; LzmaDec_Init(&p); *srcLen = inSize; res = LzmaDec_DecodeToDic(&p, outSize, src, srcLen, finishMode, status); *destLen = p.dicPos; if (res == SZ_OK && *status == LZMA_STATUS_NEEDS_MORE_INPUT) res = SZ_ERROR_INPUT_EOF; LzmaDec_FreeProbs(&p, alloc); return res; }